Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G9/00—Developers
  • G03G9/08—Developers with toner particles
  • G03G9/087—Binders for toner particles
  • G03G9/08784—Macromolecular material not specially provided for in a single one of groups G03G9/08702 - G03G9/08775
  • G03G9/08791—Macromolecular material not specially provided for in a single one of groups G03G9/08702 - G03G9/08775 characterised by the presence of specified groups or side chains
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L25/00—Compositions of, homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an aromatic carbocyclic ring; Compositions of derivatives of such polymers
  • C08L25/02—Homopolymers or copolymers of hydrocarbons
  • C08L25/04—Homopolymers or copolymers of styrene
  • C08L25/08—Copolymers of styrene
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G9/00—Developers
  • G03G9/08—Developers with toner particles
  • G03G9/087—Binders for toner particles
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G9/00—Developers
  • G03G9/08—Developers with toner particles
  • G03G9/087—Binders for toner particles
  • G03G9/08702—Binders for toner particles comprising macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • G03G9/08706—Polymers of alkenyl-aromatic compounds
  • G03G9/08708—Copolymers of styrene
  • G03G9/08711—Copolymers of styrene with esters of acrylic or methacrylic acid
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G9/00—Developers
  • G03G9/08—Developers with toner particles
  • G03G9/087—Binders for toner particles
  • G03G9/08742—Binders for toner particles comprising macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
  • G03G9/08755—Polyesters
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G9/00—Developers
  • G03G9/08—Developers with toner particles
  • G03G9/087—Binders for toner particles
  • G03G9/08742—Binders for toner particles comprising macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
  • G03G9/08764—Polyureas; Polyurethanes
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L25/00—Compositions of, homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an aromatic carbocyclic ring; Compositions of derivatives of such polymers
  • C08L25/02—Homopolymers or copolymers of hydrocarbons
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L77/00—Compositions of polyamides obtained by reactions forming a carboxylic amide link in the main chain; Compositions of derivatives of such polymers

Definitions

• This invention relates to a resin composition suitable for a toner. More particularly, it relates to a resin composition suitable as a binder for an electrophotographic toner.
• Toners disclosed in U.S. Pat. No. 5,250,382 result in a difficulty in viscosity reduction.
• a resin composition suitable for electrophotographic toner comprising:
• said resin composition has at least one Tg in the range of 50°-70° C.
• (B) has a number average molecular weight (Mnb) in the range of 500-2,500;
• SPa is the solubility parameter of (A)
• SPb is the solubility parameter of (B).
• component (A) a styrenic polymer or a copolymer of a styrenic monomer and (meth)acrylic monomer (acrylic monomer and/or methacrylic monomer may be used; similar expressions are used hereinafter) or maleic monomer.
• Suitable styrenic monomers (a) include, for example, styrene, ⁇ -methylstyrene, p-methoxystyrene, p-acetoxystyrene and p-hydroxystyrene.
• Suitable examples of (meth)acrylic monomer and maleic monomer (b) include (meth)acrylic acid; C 1-50 alkyl (meth)acrylates, such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, lauryl (meth)acrylate and stearyl (meth)acrylate; maleic acid anhydride and maleic acid monobutyl ester.
• styrenic polymer and a copolymer of a styrenic monomer and (meth)acrylic monomer. More preferred is a copolymer of a styrene and a (meth)acrylic monomer, particularly methyl (meth)acrylate or butyl (meth)acrylate.
• a weight ratio of (a) a styrenic monomer, and (b) (meth)acrylic monomer or maleic monomer, composing (A), (a)/(b) is generally (98-50)/(2-50), preferably (95-60)/(5-40).
• a weight average molecular weight (hereinafter referred to as Mw) of (A) is generally 50,000-500,000.
• a Tg of (A) is generally 50°-75° C.
• Mw of (A) is controlled so as to provide a ratio of the weight average molecular weight of said resin composition to the weight average molecular weight of (B), (Mwd/Mwb) preferably in the range of 20-1,000.
• a Mwd/Mwb lower than 20 results in a decrease of HOT, and a Mwd/Mwb over 1,000 causes poor low temperature fixing properties.
• Mw can be measured by GPC (gel permeation chromatography) using tetrahydrofuran (hereinafter referred to as THF) with use of a calibration curve of standard polystyrenes.
• a relatively lower molecular weight portion and a higher molecular weight portion may be polymerized separately, or one of these portions may be polymerized in the presence of the rest of them.
• Polymerization methods include suspension polymerization, solution polymerization and bulk polymerization.
• the weight ratio of (B)/(A) is preferably in the range of (0.01-0.5)/1, more preferably (0.02-0.4)/1.
• a (B)/(A) lower than 0.01/1 results in poor low temperature fixing properties, and a (B)/(A) over 0.5/1 causes poor thermal shelf stability.
• (B) generally has a number average molecular weight (hereinafter referred to as Mn) (Mnb) in the range of 500-2,500, preferably 800-2,400. And Mw of (B) is generally 500-7,500, preferably 800-7,000.
• a Mnb lower than 500 results in poor thermal shelf stability, and a Mnb over 2,500 causes poor low temperature fixing properties.
• the resin composition may have two or more Tg but has at least one Tg in the range of 50°-70° C. Thermal shelf stability becomes poor in case of no Tg being present at 50° C. or more while low temperature fixing properties become poor without a Tg ⁇ 70° C.
• (B) preferably has a Tg in the range of 15°-55° C., more preferably 20°-50° C., and the Tg is lower than that of (A).
• a Tg of (B) lower than 15° C. results poor thermal shelf stability, and a Tg over 55° C. causes poor low temperature fixing properties.
• a SPb-SPa lower than (-5.5 ⁇ 10 -4 Mnb+0.74) results in poor thermal shelf stabilities, because the compatibility of (A) and (B) at room temperature brings about a lower Tg.
• a SPb-SPa over -5.5 ⁇ 10 -4 Mnb+1.39 causes poor fixing properties, because (A) and (B) are not compatible even at high temperature.
• the resin composition of the invention provides improved fixing properties, because the melt viscosity of (A) is lowered by adding thereto (B), having a lower molecular weight and a lower Tg than (A).
• Sp in the invention is a repeating unit value of a polymer at 25° C. determined according to the method of Fedors. The method is disclosed by R. F. Fedors, in Polym. Eng. Sci., 14(2), 147(1974). Namely, Sp is calculated by the following equation using an evaporation energy and a molar volume of an atom and an atomic group at a structure of a compound;
• ⁇ ei is an evaporation energy of an atom or an atomic group
• ⁇ vi is a molar volume of an atom or an atom group.
• Suitable polar groups of (B) of the invention include, for example, hydroxyl group, carboxyl group, sulfonic acid group, amino group, amide group, epoxy group and nitrile group. Among these, hydroxyl group and carboxyl group are preferred.
• polymers suitable as component (B) include polyester, copolymer of styrene with (meth)acrylate monomer, styrenic polymer, (meth)acryl polymer, epoxy resin, polyurethane resin, polyamide resin and polycarbonate resin.
• polyester, copolymer of styrene with (meth)acrylate monomer, styrenic polymer, polyurethane resin and polyamide resin particularly polyester, polyurethane resin and polyamide resin.
• Suitable examples of a polyester of the invention are inclusive of polycondensation products of a diol with dibasic acid (or ester forming derivative thereof).
• Suitable diols include low molecular weight diols, for example, (1) aliphatic dihydric alcohols (glycols), such as ethylene glycol, propylene glycol, 1,3- and 1,4-butane diols, 1,6-hexane diol, neopentyl glycol, 3-methyl-1,5-pentane diol, diethylene glycol and triethylene glycol, (2) dihydric phenols, such as hydroquinone, catechol, resorcinol, pyrogallol, and bisphenols (e.g.
• bisphenol A bisphenol AD, bisphenol F and bisphenol S (bisphenol sulfone)
• cycloaliphatic dihydric alcohols such as 1,4-dihydroxymethylcyclohexane, and hydrogenated bisphenols
• EO and PO alkylene oxide
• ethylene glycol, neopentyl glycol and alkylene oxide adducts preferably 2-3 moles adducts of bisphenols (particularly bisphenol A), and mixtures of them. More preferred are alkylene oxide 2-3 moles adducts of bisphenol A, neopentyl glycol, and mixtures of them.
• Suitable dibasic acids include dicarboxylic acids, for example, aliphatic, aromatic and cycloaliphatic ones, such as succinic, maleic, fumaric, itaconic, azelaic, mesaconic, citraconic, sebacic, glutaconic, adipic, malonic, glutaric, phthalic, isophthalic, terephthalic, cyclohexane dicarboxylic, nadic and methyl-nadic acids, alkyl- or alkenyl (C 1-20 )-succinic acids (e.g.
• octyl-succinic and dodecenyl-succinic acids and dimer acids, obtainable by dimerization of fatty acids (such as linoleic and linolenic acids); and mixtures of 2 or more of these acids; as well as ester-forming derivatives of these acids, for instance, anhydrides and lower alkyl esters, such as maleic and phthalic anhydrides, dimethyl terephthalate and the like.
• succinic, maleic, fumaric, phthalic, isophthalic, terephthalic, and alkyl- or alkenyl (C 4-18 )-succinic acids are preferred.
• Polycondensation of diol with dibasic acid or ester-forming derivatives thereof can be carried out under known conditions, for instance, at a temperature of usually 150°-300° C., with or without a catalyst (such as dibutyltin oxide, stannous oxide, tetrabutyl titanate and so on), under normal or reduced pressure, in the absence or in the presence of an inert gas or solvent.
• a catalyst such as dibutyltin oxide, stannous oxide, tetrabutyl titanate and so on
• acid anhydride can be reacted in order to increase the amount of terminal carboxyl group of polyester, otherwise to decrease the amount of terminal hydroxyl group.
• Preferred acid anhydride is succinic acid.
• an acid number (hereinafter referred to as AV) is generally 0.5-224 mg KOH/g, preferably 0.5-140 mg KOH/g, and a hydroxyl number (hereinafter referred to as OHV) is generally 0.5-224 mg KOH/g, preferably 0.5-140 mg KOH/g.
• Suitable vinyl monomers having a polar group used for a copolymer of a styrenic monomer with an ester of (meth)acrylic acid, (meth)acrylate and styrenic polymer of (B) include 2-hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, 2-hydroxy-3-phenyloxy-propyl(meth)acrylate, hydroxybutyl (meth)acrylate, reaction products of glycidyl (meth)acrylate with (meth)acrylic acid, polyethyleneglycol (meth)acrylate, polypropyleneglycol (meth)acrylate, maleic anhydride, monobutyl maleate, (meth)acrylamide, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, (meth)acrylonitrile and p-hydroxystyrene.
• (B) can also be obtained by introducing polar groups into polymers containing no polar group, such as a copolymer of styrene with (meth)acrylate, (meth)acrylate polymer and styrenic polymer.
• Illustrative examples of such polymers include (1) ones containing a hydroxyl group introduced thereinto, such as a resin of a hydrolyzate of a copolymer of p-acetoxystyrene, and (2) ones containing a sulfonyl group introduced thereinto, such as a sulfonated product of a styrenic copolymer with chlorosulfonic acid.
• Suitable examples of polyurethane resin of the invention are inclusive of polyaddition products of an organic diisocyanate with a diol.
• Suitable organic diisocyanates include, for example, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate and tetramethylxylylene diisocyanate.
• tolylene diisocyanate and diphenylmethane diisocyanate are preferred.
• Suitable diols include, for example, above-mentioned dihydric alcohols. Among these, bisphenol EO and/or PO 2-4 mole adducts are preferred.
• the polyaddition reaction is generally carried out at 40°-130° C., and can use catalysts such as dibutyltin dilaulate and stannous octoate.
• a NCO index of polyurethane resin is generally 50-120, preferably 60-90.
• monohydric alcohol such as C 1-18 aliphatic alcohols
• organic monoisocyanate to block terminal isocyanate group or terminal hydroxyl group.
• Examples of a polyamide resin are (1) a ring opening polymer of a lactam, (2) a polycondensate of an aminocarboxylic acid or (3) a polycondensate of a dicarboxylic acid and a diamine.
• lactams (1) are caprolactam, enantholactam, laurolactam and undecanolactam.
• Examples of aminodicarboxylic acids (2) are ⁇ -aminocaproic acid, ⁇ -aminoenanthic acid, ⁇ -aminocaprylic acid, ⁇ -aminopelargonic acid, ⁇ -aminocapric acid, 11-aminoundecanoic acid and 12-aminododecanoic acid.
• Dicarboxylic acids of (3) for example, can be used as used for above-mentioned polyesters.
• diamines of (3) for example, are aliphatic diamines (such as ethylene diamine, diethylene triamine, triethylene tetramine, hexamethylenediamine, heptamethylene diamine, octamethylene diamine and decamethylene diamine), alicyclic diamines (such as isophrone diamine) and aromatic diamine (such as xylyene diamine).
• aliphatic diamines such as ethylene diamine, diethylene triamine, triethylene tetramine, hexamethylenediamine, heptamethylene diamine, octamethylene diamine and decamethylene diamine
• alicyclic diamines such as isophrone diamine
• aromatic diamine such as xylyene diamine
• ) reaches 10,000 poises (hereinafter referred to as T ⁇ ), is preferably higher by at least 10° C., more preferably by at 15° C., than that of (B), from a view point of low temperature fixing properties.
• can be measured by a dynamicviscoelastmeter, for instance, RDS-7700II DYNAMICSSPECTROMETER (Rheometrics Inc. U.S.A.).
• the resin composition preferably has a Tg lower by 1°-10° C. than that of (A), in view of a balance of the low temperature fixing properties and the thermal shelf stabilities. More preferred are 2°-8° C. lower.
• Blending methods of (A) with (B) are not particularly restricted, and include, for example (1) kneading (A) and (B) at molten states under heating, (2) blending them in the presence of an organic solvent, followed by distillation of the solvent, (3) polymerizing one of them in the presence of the other.
• the resin composition of this invention may further contain a compatibilizer (C).
• suitable (C) include graft or block copolymers having a block of styrenic polymer and/or copolymer of styrenic monomer with (meth)acrylate, and a block of the same polymer as (B).
• Mw of (C) is generally 2,500-100,000.
• a weight of (C) is generally 0-120% based on (B).
• Illustrative synthetic methods of (C) include, in case (B) is polyester, (1) a method by polymerizing styrenic monomer and/or (meth)acrylate in the presence of a polyester (B) and a terminal double bond-containing polyester (D) prepared by reacting methacryloxy isocyanate with an OH group of a polyester produced in the same composition and polymerization method as (B); and (2) a method by polymerizing styrenic monomer and/or (meth)acrylate in the presence of a polyester containing a polymerizable double bond introduced thereinto with use of an unsaturated component such as maleic anhydride.
• the resin composition of the invention may contain low molecular weight polyolefin (such as polyethylene and polypropylene) in an amount of 1-10% based on the total weight of the resin composition. But, measurement of molecular weight of the resin composition is carried out without the low molecular weight polyolefin.
• low molecular weight polyolefin such as polyethylene and polypropylene
• Formulations of electrophotographic toners wherein the resin composition of the present invention is used, include, for example, ones comprises generally 45-95% by weight of the resin composition, usually 5-10% by weight of known colorants (such as carbon black, ion black, benzidine yellow, quinacridone, rhodamine B, phthalocyanine and the like), and generally 0-50% by weight of magnetic powders (such as iron, cobalt, nickel, hematite, ferrite and the like).
• known colorants such as carbon black, ion black, benzidine yellow, quinacridone, rhodamine B, phthalocyanine and the like
• magnetic powders such as iron, cobalt, nickel, hematite, ferrite and the like.
• additives for example, charge controllers (such as metal complexes and nigrosine), lubricants (such as polytetrafluoroethylene, low molecular weight polyolefins, fatty acids and metal salts or amides thereof), and so on).
• charge controllers such as metal complexes and nigrosine
• lubricants such as polytetrafluoroethylene, low molecular weight polyolefins, fatty acids and metal salts or amides thereof
• the amount of these additives is usually 0-10% by weight based on the weight of toner.
• Electrophotographic toner can be prepared by dry blending these components and then kneading under melt, followed by crushing and then finely pulverizing with a grinder, such as a jet grinder, into fine particles of 5-20, ⁇ m diameter.
• a grinder such as a jet grinder
• the electrophotographic toner can be optionally mixed with carrier particles, such as iron powder, glass beads, nickel powder, ferrite and the like, and used as a developer for electrical latent images.
• carrier particles such as iron powder, glass beads, nickel powder, ferrite and the like
• a hydrophobic colloidal silica powder may be used to improve flowability of powders.
• the electrophotographic toner can be used by fixing on substrates (such as paper, polyester film and the like). Fixation means are mentioned above.
• parts and ratio mean parts by weight and weight ratio, respectively.
• Sample solution 0.5% THF solution.
• Amount of solution 200 microliters.
• Mw calibration curve was prepared using standard polystyrene.
• Test fixture cone and plate, 25 mm ⁇
• polyesters (B-3)-(B-11) were obtained. Those component and ratio were shown in Table 1, and results of the measurements were shown in Table 2.
• the mixture was heated under stirring to a reflux temperature, and stirring was continued for additional 4 hours under reflux. Thereafter, the volatile materials were distilled off under normal pressure heating up to 180° C. and then under reduced pressure at 180° C., followed by continuing distillation for 1.5 hours after reaching 20 torrs.
• binder resin (A-1) having Mn of 3,800, Mw of 180,000, Tg of 62° C., and T ⁇ of 121° C., and calculated solubility parameter (SPa) was 10.03.
• each resin (B) shown in Table 2 Into a flask equipped with a condenser and a stirrer, were charged each resin (B) shown in Table 2, and the resin (A-1) or (A-2), in a ratio shown in Table 3, followed by substituting the atmosphere in the flask with nitrogen, then adding 120 parts of xylene and further substituting the atmosphere with nitrogen.
• toners of Examples a-h of the invention exhibited well balanced low temperature fixability and cohesiveness as compared with toners of Comparative Examples i-o, and improved dispersability and charging properties as compared with toners of Comparative Examples i-o.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Spectroscopy & Molecular Physics (AREA)
• Health & Medical Sciences (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Developing Agents For Electrophotography (AREA)
• Compositions Of Macromolecular Compounds (AREA)

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• 1994
  • 1994-02-17 JP JP6044871A patent/JP2850093B2/ja not_active Expired - Fee Related
• 1995
  • 1995-02-16 EP EP95102192A patent/EP0672956B1/de not_active Expired - Lifetime
  • 1995-02-16 CN CN95102108A patent/CN1111019A/zh active Pending
  • 1995-02-16 DE DE69521352T patent/DE69521352T2/de not_active Expired - Fee Related
  • 1995-02-17 US US08/390,572 patent/US5595849A/en not_active Expired - Lifetime

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